1. Field of the Invention
The present invention relates to a safety clasp knife, and more particularly to the clasp knife having a positioning rod movably mounted in the handle to allow the positioning rod to be alternatively fixed relative to the blade such that the blade is able to be foldable relative to the handle.
2. Description of Related Art
With reference to FIGS. 7 and 8, a conventional clasp knife includes a handle (80) and a blade (90).
The handle (80) has a receiving space (81) defined in the handle (80) to alternatively receive therein the blade (90), a stop (82) formed on a side face of the handle (80), and a position slot (84) defined through the handle (80).
The blade (90) has a boss (91) formed on a distal end of the blade (90) to be received in the position slot (84) of the handle (80) and a spring (92) having a first distal end abutted in an inner face of the handle (80) and a second distal end abutted to the boss (91).
The blade (90) is pivotally received in the handle (80) with the spring (92) being compressed by the boss (91). However, when the blade (90) is extended out of the handle (80), due to the abutment of the spring (92) to the boss (91), the boss (91) is able to move within the position slot (84) from a first position to a second position until the blade (90) is fully extended.
When the blade (90) is folded, the operator has to push the blade (90) toward the handle (80) first to allow the boss (91) to leave the second position to compress the spring (92). After the boss (91) leaves the limitation of the second position, the blade (90) is able to be pivoted and received inside the receiving space (81) of the handle (80).
When the clasp knife is operated, in order to allow the operator to operate the pivotal movement of the blade (90), the blade (90) has a large portion revealed outside, which spoils the overall appearance. Furthermore, after a long period of time using the clasp knife, the periphery of the position slot may become worn and thus the boss may not be limited by the position slot. Accordingly, the blade (90) may be pivoted relative to the handle (80) even when the blade (90) is not moved toward the handle (80) first to release the limitation of the position slot (84) to the boss (91), which is very dangerous to the operator and is a design flaw.
The spring is also exposed outside the handle such that the spring escapes easily from the knife.
Due to the formation of the boss and the adaptation made to the blade to cope with the spring, the appearance of the clasp knife does not have much room for change and improvement.
To overcome the shortcomings, the present invention tends to provide an improved safety clasp knife to mitigate the aforementioned problems.
The primary objective of the present invention is to provide an improved safety clasp knife having a blade pivotable relative to the handle. The handle has a positioning rod movably received in the handle such that the positioning rod is able to alternatively move from a first position to a second position or from the first position to a third position in the blade to allow the blade to pivot relative to the handle.
In order to accomplish the above objective, the blade is composed with a through hole, a first limiting notch defined in a periphery defining the through hole and a second limiting notch defined in a periphery defined the through hole and opposite to the first limiting notch. Therefore, the positioning rod received in the through hole of the blade is able to move to the first limiting notch or the second limiting notch due to the drive of the springs especially when the blade is fully extended outside the handle or fully received in the handle.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.